几种简单的排序

花了些时间复习了下排序，记录来吧，权当巩固之用~

using System;
class sort
{
    static void Main() 
    {
        var arr = IntiArray();
        BubbleSort(arr);
        arr = IntiArray();
        insertSort(arr);
        arr = IntiArray();
        SimpleSelectSort(arr);
        arr = IntiArray();
        QucikSort(arr, 0, arr.Length - 1);
    }
    public static int[] IntiArray() 
    {
        Random ran = new Random();
        int[] arr = new int[10];
        for (int i = 0; i < 10;i++ )
        {
            arr[i] = ran.Next(1, 100);
        }
        return arr;
    }
    public static int[] BubbleSort(int[] arr) 
    {
        int i, j;
        for (i = 0, j = arr.Length; i < j;i++ )
        {
            bool flag = false;
            for (int k = j-1; k > i;k--)//index一定要对好
            {
                if(arr[k]<arr[k-1])
                {
                    int temp = arr[k - 1];
                    arr[k - 1] = arr[k];
                    arr[k] = temp;
                    flag = true;//注意此处要变化flag
                }
            }
            if(!flag)
            {
                return arr;
            }
        }
        return arr;
    }
    public static int[] insertSort(int[] arr)
    {
        for (int i = 0, j = arr.Length; i < j-1;i++ )
        {
            int temp = arr[i + 1];
            int k = i;
            while (k >= 0 && temp < arr[k])
            {                
                arr[k + 1] = arr[k];
                k--;
            }
            arr[k + 1] = temp;
        }
        return arr;
    }
    public static int[] SimpleSelectSort(int[] arr) 
    {
        for (int i = 0, j = arr.Length; i < j;i++ )
        {
            int t = i;
            for (int k = i + 1; k < j;k++ )
            {
                if(arr[t]>arr[k])
                {
                    t = k;//最小的下标保存在t中
                }
            }
            int temp = arr[i];
            arr[i] = arr[t];
            arr[t] = temp;
        }
        return arr;
    }
    public static int Partition(int[] array,int low,int high) 
    {
        int i = low;
        int j = high;
        int pivot = array[low];
        while(low<high)
        {
            while(low<high&&array[high]>pivot)
            {
                --high;
            }
            array[low] = array[high];
            while(low<high&&array[low]<pivot)
            {
                ++low;
            }
            array[high] = array[low];
        }
        array[low] = pivot;
        return low;
    }
    public static int[] QucikSort(int[] array,int low,int high) 
    {
        if(low<high)
        {
            int pivotKey = Partition(array,low,high);
            QucikSort(array, low, pivotKey - 1);
            QucikSort(array, pivotKey + 1, high);
        }
        return array;
    }
   
}